Instead of creating a new process for each request, FastCGI uses persistent processes to handle a series of requests. These processes are owned by the FastCGI server, not the web server. 1

To service an incoming request, the web server sends environment information and the page request itself to a FastCGI process over a socket (in the case of local FastCGI processes on the web server) or TCP connection (for remote FastCGI processes in a server farm). Responses are returned from the process to the web server over the same connection, and the web server subsequently delivers that response to the end-user. The connection may be closed at the end of a response, but both the web server and the FastCGI service processes persist.2

Each individual FastCGI process can handle many requests over its lifetime, thereby avoiding the overhead of per-request process creation and termination. Processing of multiple requests simultaneously can be achieved in several ways: by using a single connection with internal multiplexing (i.e. multiple requests over a single connection); by using multiple connections; or by a combination of these techniques. Multiple FastCGI servers can be configured, increasing stability and scalability.

it almost certainly could never be thread-safe.

If you describe why you think you need threads, maybe we can help.

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.